Porous media, particularly microporous membranes, are used to filter a variety of fluids. During the course of filtering fluids, the porous media eventually become clogged or plugged with impurities and/or other fluid components. This is particularly a problem in the filtration of protein-containing fluids. Natural proteins, such as those in milk, beer, and wine, can quickly plug porous media such as microporous membranes.
While a clogged filtration medium can be replaced, the costs involved in such replacement can be quite significant. Thus, many techniques have been developed to unclog porous media, e.g., by forwardwashing or backwashing with water, usually at high pressure and elevated temperatures. The more severe the unclogging procedure, however, the greater the cost to use the procedure. Also, since many porous media such as microporous membranes are rather delicate, severe unclogging conditions can damage the porous medium, thereby rendering it useless. The use of fluids other than water to clean the porous medium could similarly damage the porous medium or even introduce contaminants into the fluid being filtered unless entirely removed from the thus cleaned porous medium.
Accordingly, there remains a need for a method of unclogging a porous medium, particularly a microporous membrane, which will not damage the porous medium. Such a method should also not run the risk of introducing contaminants into the porous medium and/or fluid being filtered by the porous medium. The method of treating a clogged porous medium should also be such that it can be efficiently and economically used. The present invention provides such a method of treating a clogged porous medium.
These and other objects and advantages of the present invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.